— 84 — In morphological characteristics the type found in the Sudan does not differ greatly from the European form. It resists desiccation to a remarkable degree, although no definite sporihg stage has ever been found. A dried-up culture was found to be still active, after having been kept in an incubator for eighteen months. The distribution of this type at various depths was studied in the " Duty of "Water " experiment where the effect of irrigation could also be ascertained.

Soil was taken aseptically from three plots : No. I. was receiving 500 cubic metres every 10 days.

No. II. „ „ 400 No. III. „ „ 300 In each case samples were taken from the surface, 50, 100, 200 and 300 cm.

The results were as follows :